A valve type which is already known consists of two laminar strips of different lengths which are joined together by lengthwise weld lines. This forms a laminar valve shaped like a tube with one end open for the intake of gas which is accessible from the outside and one outlet end opening into the inside of the balloon. On the entry end of the valve there is a flap made up of an extension of one of the strips. This protects the balloon sheet like material to which the valve is welded. Moreover, in the area next to the end of the valve input one of the strips has an non-weldable covering which reaches a location close to the flap. Thus, when the valve is being welded to one of the sheets which make up the balloon the opening is not blocked.
One problem with this type of valve is that the protective flap on the end of the entry opening does not sufficiently prevent damages to the balloon when the inflation nozzle is used.
Another problem concerns the correct placing of the prefabricated valve into one of the internal faces of the balloon in order to weld together the valve and the sheets which make up the balloon. These problems with positioning make it difficult to obtain a fast and efficient production process.